Problem: Kevin starts counting at 33, and he counts by threes. If 33 is the 1st number that Kevin counts. what is the 11th number that he counts?
Solution: What is the first number that he counts? $33$ What is the second number that he counts? $\begin{align*}&33 + 3 \\ &= 36\end{align*}$ What is the third number that he counts? $\begin{align*}&33 + 3 + 3 \\ &= 33 + (2 \times 3) \\ &= 39\end{align*}$ What is the 11th number that he counts? $\begin{align*}&33 + (10\times3) \\ &= 33 + 30 \\ &= 63\end{align*}$